Programming

#include<iostream>
#include<string>
#include<sstream>
#include<sys/types.h>
#include<sys/socket.h>
#include<netdb.h>
#include<arpa/inet.h>
#include<errno.h>
using namespace std;


struct addrinfo hints;          //fill your host info - hints is input
struct addrinfo *results;        //gets your host info - results is output
char *remoteIP = new char[40];  //holds inserted remote IP
string tempPort;                //holds ports temporarly
int startingPort;               //stores the starting range of port number
int status;                     //receives the status of your pc address
int currentPort;                //holds current port

//program description
void progDesc()
{
     cout<<"This is a simple port scanner, scan range of\n";
     cout<<"ports on your local machine...\n"<<endl;

}


//getaddrinfe locates your machine, more specific
//details of your host address is returned to results. 
void getAddrIn()
{
    status = getaddrinfo(remoteIP, NULL , &hints, &results);

    if(status != 0)
    {
        fprintf(stderr, "getaddrinfo error: %s\n", gai_strerror(status));
        exit(1);
    }
}


//Run the program
int main()
{
    int endingPort;                 //stores the ending rage of port number

    system("clear");

    //tell user what program does
    progDesc();
    
    //set size of hints to zero
    memset(&hints, 0, sizeof hints);

    //fill some of your host address info
    hints.ai_family = AF_UNSPEC;
    hints.ai_socktype = SOCK_STREAM;

    //ask for remote IP
    cout<<"Please enter your target IP: ";
    cin>>remoteIP;

    //call get addrinfo()
    getAddrIn();

    //ask port range from user
    cout<<"Enter Starting Port: ";
    cin>>startingPort;

    cout<<"Enter Ending Port: ";
    cin>>endingPort;

    cout<<endl;

    cout<<"Start Scanning: "<<endl;

    //check the status
    while(startingPort <= endingPort)
    {
        //call getaddrinfo()
        getAddrIn();

        //create a socket.
        int socketfd;
        socketfd = socket(results->ai_family, results->ai_socktype, results->ai_protocol);

        if(socketfd == -1 )
        {
            cout<<"Error: failed to create a socket.\n";
            return 2;
        }

        //********************************************************************
        //add a specific port, you want to connect to, for the remote host
        struct sockaddr_in *specifyPort = (struct sockaddr_in *)results->ai_addr;
        specifyPort->sin_port = htons(startingPort);

        //make connection to host IP/Port specified
        int connectStatus;
        connectStatus = connect(socketfd, results->ai_addr, results->ai_addrlen);
    
        if(connectStatus == -1 )
        {        
            if(errno == ECONNREFUSED)
                cout<<"Port "<<startingPort<<" is Closed or Blocked.\n";
            else if(errno == ETIMEDOUT)
                cout<<"The attempt to connect TIMED OUT before a connection was made."<<endl;
            else
                cout<<"Error: "<<strerror(errno)<<endl;
        }else{
            cout<<"Port "<<startingPort<<" is OPEN.\n";
        }
        //**********************************************************************

        close(socketfd);
    
        //move to the next port in the specified range
        startingPort++;

    }

    //deallocate memory
    delete[] remoteIP;

    //free linkedlist of struct addrinfo *results 
    freeaddrinfo(results);

    return 0;
}